The present invention relates generally to a drain box and, more particularly, to a drain box for a roof of a building designed to improve drainage of rain water, for example, to and through a downspout.
It is well known that a generally flat or slightly sloped roof of a building or other structure is particularly susceptible to puddling or pooling of rain water. Such occurrences are relatively common, particularly with commercial and industrial buildings, as well as domestic structures, such as townhomes or row homes, and often cause leaks into the interior of the buildings. Although generally flat-roof buildings may include a downspout, which may be in the form of a cylindrical tube or a tube having a square or rectangular cross-section having a top end or opening located at or near the roof surface and a bottom end or opening that extends toward the bottom of the building, the downspout can become easily clogged with debris, such as leaves and twigs, for example, or other objects, such as balls, for example.
Various devices are used to improve the drainage of rain water to and through the downspout. For example, U.S. Pat. No. 5,735,091 to Hawkins et al. discloses a metal dome-shaped “cap” or raised cage which can be placed over the top end of the downspout. The caps are designed to permit the flow of rain water to the top end of the downspout, but block the flow of leaves and twigs, for example, into the downspout. However, leaves, twigs or other debris often clog the cap, thus defeating the purpose of the cap.
Referring to FIGS. 1, 9 and 11, another prior art device used to improve drainage on a flat or generally flat roof 50 is generally referred to as a “drain box” 210. The prior art drain box 210 is a generally elongated, rectangular structure having an open top, a first portion 212a designed to be placed over or around a top end 42a of a downspout 42 and a second portion 212b designed to initially receive the water to be drained. The second portion 212b extends along a portion of the roof 50 away from the top end 42a of the downspout 42. A bottom wall 224 of the first portion 212a extends generally parallel to and coplanar with a bottom wall 226 of the second portion 212b. Although the drain box 210 is designed to provide an open/clear passageway to the top end 42a of the downspout 42, at least the first portion 212a of the drain box 210 often becomes clogged with any or all of leaves, twigs or other debris after a heavy rainstorm, for example, or simply over an extended period of time, thus preventing water from draining from the roof to and through the downspout 42.
As seen in FIGS. 9-12 and 16, generally flat-roof buildings 52, such as any or all of commercial or industrial buildings or townhouses or row homes, typically include one or more firewalls, parapet walls or property walls 58 that extend upwardly a predetermined distance beyond the level of the roof 50 at or around the perimeter thereof. The parapet walls 58 may extend 30 inches above the level of the roof 50, depending on the building codes of the particular jurisdiction. The parapet walls 58 help to direct rain water, for example, toward at least one section of the roof 50 such that rain water can flow directly off of the roof 50 or toward or to a downspout 42, if provided.
However, using a conventional drain box 210 on a roof 50 that includes parapet walls 58 generally surrounding the perimeter thereof can be problematic. For example, if any or typically all of leaves, twigs or other debris, for example, clogs or blocks the first portion 212a of the drain box 210, the rain water can quickly accumulate on the roof 50, since the parapet walls 58 generally prevent the rain water from flowing off of the roof 50 until the water level reaches the necessary height to flow over the parapet walls 58 (i.e., thirty inches) or a front end wall 216a of the drain box 210. This relatively large accumulation of rain water may, particularly over time, result in a weight that can literally crush portions of the roof 50, causing at least portions of the roof 50 to cave into the interior of the building 52.
Therefore, it would be desirable to create a device that eliminates, or at least reduce, the above-identified deficiencies. The present invention does so.